Imaging devices that form images on media by ejecting colorant onto media make use of one or more printheads. The printheads include arrays of nozzles that have openings coupled to chambers. Adjacent to the chambers are resistive elements used for heating the ink to cause the ink in the chambers to eject from the nozzles. The quality of the image formed from the ejected ink is influenced by the consistency in the quantity of ink ejected from the nozzles. The consistency in the quantity of ink ejected from the nozzles is affected by the temperature of the chambers. Temperature related adjustment of the power supplied to the resistors can at least partially compensate for temperature related variation in the quantity of ink ejected from the nozzles and for changes in the operating temperature of the printhead. Inaccuracies in the measurement of the temperature of the printhead can reduce the effectiveness of the compensation for temperature related changes in the quantity of ink ejected from the nozzles.
An apparatus includes a substrate and a resistive element attached to a region of the substrate and formed of a first material having a first temperature coefficient of resistivity. In addition, the apparatus includes a pair of traces coupled to the resistive element, attached to the substrate, and formed of a second material having a second temperature coefficient of resistivity with the first material selected so that the first temperature coefficient of resistivity exceeds the second temperature coefficient of resistivity.
An apparatus includes a substrate and a resistive element disposed onto a first region of the substrate and formed of a first material having a first temperature coefficient of resistivity. In addition, the apparatus includes a pair of traces coupled to the resistive element and each formed of a first plurality of sections of a second material having a second temperature coefficient of resistivity and a second plurality of sections of a third material having a third temperature coefficient of resistivity.